Progressive multifocal lenses as used in eyeglasses, or spectacles, comprise, along a principle meridian curve; a farsighted vision zone having an optical power corresponding to that required for viewing distant objects; a nearsighted vision zone having an optical power corresponding to that required for viewing near objects; and an intermediate vision zone between and progressively connecting the farsighted vision zone and the nearsighted vision zone. Progressive eyeglasses thus ensure different optical powers in upper and lower portion of each spectacle lens gradually increasing towards the lower periphery. However, strong problems with aberration correction exist. The oblique rays of near objects pass through the spectacle lens at peripheral parts such that they usually produce astigmatism and/or other aberrations. The degree of astigmatism is also high for the right and left peripheral parts of the spectacle lens responsible for side vision, thus loosing comfort in vision.
Traditional technology for spectacles lens fabrication based on refractive optics provides very limited possibilities in aberration correction. The important parameters: optical power, near and far vision ability, lens thickness, and aberration rate, are in a tradeoff relation and cannot be achieved all together. For example changing the local slope of the lens surface for aberration correction immediately influences lens thickness and might change also optical powers for far or/and near vision.